Despite its claims, Multimedia Messages, from Hook Mobile, is not a multimedia messaging service for the iPhone.
Here's what Hook says Multimedia Messages does: Sends picture messages from your iPhone to the telephone numbers of your friends and delivers messages as MMS, "which means no links to click" (their words).
Here's how it works: Launch Multimedia Messages and you'll immediately go to a screen with three options: Send photo, open camera and open address book. Take a picture, enter the telephone number of your friend, type a message and drop the image into the message and send.
What happens next is the app sends a text message to your friend with a link. Your friend taps the link, which takes him or her to Hook's Web site to view the message and image. It's not true MMS, unless there something about this process that I just don't get.
True MMS enables you to send messages that include text, images, audio text and other multimedia objects. Multimedia Messages obviously isn't capable of doing that. About the only thing Multimedia Messages has in common with MMS is that it uses SMS (an extension of MMS) and it puts content on a server where it's temporarily stored. MMS goes beyond that to forward the message and its objects to your friend's smartphone where it's opened (there's more to it that that, but you get the point).
I suspect most people would rather use the native apps to take a photo and email it to their friend, bypassing SMS entirely. The plain-vanilla way of doing it is faster than using Multimedia Messages too.
Multimedia Messages works fine. It's a simple-to-use mobile app and Web service that you use to send messages and images. There's no value added here, even though the app is free.
I think the problem most people have with Multimedia Messages is not that it doesn't work but that Hook Mobile has exaggerated its capabilities to get this app on the iPhones of the unsuspecting. It seems to be more of a marketing tactic than anything else.